U–Pb and Hf isotopic data from Franklinian Basin strata: insights into the nature of Crockerland and the timing of accretion, Canadian Arctic Islands

Abstract

New detrital zircon uranium–lead (U–Pb) ages and initial epsilon hafnium (εHf(i)) data from the Devonian clastic succession of the Canadian Arctic Islands refines the provenance of strata within the Franklinian Basin and provides constraints on the geologic evolution of the landmass responsible for the Ellesmerian Orogen. This study contributes more than 500 U–Pb ages and 32 εHf(i) values from the Blackley Formation and the Parry Islands Formation. The Middle Devonian Blackley Formation represents the onset of clastic sedimentation into the Franklinian Basin during the Devonian period. Detrital zircon from two samples yield U–Pb age populations of 380–470, 500–700, 900–2100, and 2550–3000 Ma. The population of 500–700 Ma U–Pb ages indicates a source exotic to the northern Laurentian margin and is attributed to a continental landmass located north of the present Canadian Arctic Islands (often referred to as Crockerland). This is some of the earliest evidence of 500–700 Ma detrital zircon deposition onto the northern Laurentian margin and indicates this northern landmass is at least partially accreted to Laurentia by early-Eifelian time. The Late Devonian Parry Islands Formation is the uppermost succession of Ellesmerian Orogen foreland basin sedimentation in the Franklinian Basin. Detrital zircon from four samples yield U–Pb age populations of 370–450, 470–750, 930–2100, and 2300–3200 Ma. The U–Pb ages suggest the Parry Islands Formation is derived from the northern source terrane (Crockerland) and indicate this landmass contains rocks similar to that of the east Greenland Caledonides, Pearya, and northeastern Baltica. Rim and core U–Pb double dates from the 500–700 Ma detrital zircon population and εHf(i) values from the 380–450, 520–550, and 650–710 Ma detrital zircon populations help constrain magma generation processes within Crockerland and suggest the zircons are derived from a juvenile lithosphere.

Closing the Canada Basin: Detrital zircon geochronology relationships between the North Slope of Arctic Alaska and the Franklinian mobile belt of Arctic Canada

“…In order to test the rotational opening hypothesis for the Canada Basin, we carried out detrital zircon geochronology of northerly-derived strata deposited along the northern margin of Arctic Alaska. We then compared these data to recently published detrital zircon data sets from Paleozoic to Mesozoic strata of the Canadian Arctic and northernmost Cordilleran margins of Laurentia (Miller et al, 2006;Beranek et al, 2010aBeranek et al, , 2010bLemieux et al, 2011;Omma et al, 2011;Malone, 2012;Anfi nson et al, 2012aAnfi nson et al, , 2012b. Analysis of the data obtained from Mississippian to Jurassic strata deposited across northern Alaska supports a consistent source for these sediments through time and along strike.…”

“…Likewise, during the timeframe in which the pre-Mississippian unconformity was being cut into the Franklinian megasequence in northern Alaska, northerly-derived (from a Canadian reference frame) strata deposited in the adjacent western Canadian Arctic Islands could have been sourced from Franklinian strata of the Arctic Alaska margin. Beranek et al (2010a) and Anfi nson et al (2012aAnfi nson et al ( , 2012b have argued that the presence of non-Laurentian affi nity zircon populations in the northerly-sourced Devonian clastic wedge of northern Yukon and the Canadian Arctic Islands may have been derived from "Crockerland," a composite terrane that could have included today's Alaskan margin of the Canada Basin ( Fig. 4).…”

“…A la s k a n M a rg in A la s k a n M a rg in A la s k a n M a rg in A la s k a n M a rg in C a n a d ia n M a r g in C a n a d ia n M a r g in C a n a d ia n M a r g in C a n a d ia n M a r g in the Ellesmerian orogen to the north, which, in addition to likely recycling deformed Franklinian basin strata, also supplied non-Laurentian affi nity detritus and recycled Caledonian orogen material onto a tectonically subsiding Canadian Arctic foreland basin (Anfi nson et al, 2012a(Anfi nson et al, , 2012b. Much of the northern (hinterland) part of the Ellesmerian orogenic belt is assumed to have been rifted away from Arctic Canada during Mesozoic time, and is referred to as "Crocker land" (Embry, 1990(Embry, , 2009Anfi nson et al, 2012aAnfi nson et al, , 2012b.…”

New data on detrital zircons from the sandstones of the lower Cambrian Brusov Formation (White Sea region, East-European Craton): unravelling the timing of the onset of the Arctida–Baltica collision

“…Upon secondary resedimentation, these materials might have reached very distant parts of this continent and later appeared within Arct-Laurussia and Arct-Laurasia. This hypothesis (Kuznetsov 2006) finds support in age studies of detrital zircons from Palaeozoic and early Mesozoic (Triassic) sedimentary units deposited on Arctica: the pU-T signal has been detected in many localities, up to very distal Canadian Arctic archipelago, Alaska and Chukotka (Miller et al 2006;Lorenz et al 2008;Amato et al 2009;Anfinson et al 2012aAnfinson et al , 2012bAnfinson et al , 2013. A summary of U-Pb ages for detrital zircons from the Ediacaran(?…”

A Practical Approach for Collecting Large‐n Detrital Zircon U‐Pb Data sets by Quadrupole LA‐ICP‐MS

“…, Afinson et al . ), identifying displaced crustal fragments (e.g., Housen and Beck , Garver and Davidson ) and for constraining the maximum depositional ages of sedimentary units (Dickinson and Gehrels ). Early detrital zircon U‐Pb studies utilised isotope dilution‐thermal ionisation mass spectrometry (ID‐TIMS) of individual and multi‐grain zircon fractions (e.g., Girty and Wardlaw , Gehrels and Ross ).…”